Object Marking for Optical Authentication and Method for Producing Same

ABSTRACT

Object marking, and method for producing same, for optical authentication of an object, wherein at least one section of a material piece of a basic material is determined arbitrarily or randomly and the object marking is produced with the at least one section, and wherein the basic material of the material piece has a repeating security feature having optical properties dependent on the viewing angle, the dimensions of said security feature being larger than the dimensions of the section, more particularly larger than the dimensions of the object marking, such that each section is unique and has only a part of the security feature.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/062,782, filed 5 Oct. 2020, which is a divisional application of U.S.patent application Ser. No. 15/039,950 filed 27 May 2016, which is anational phase application under 35 U.S.C. § 371 of InternationalApplication No. PCT/EP2014/075916 filed 28 Nov. 2014, which claimspriority to European Patent Application No. 13194863.0 filed 28 Nov.2013. The entire contents of each of the above—referenced disclosures isspecifically incorporated by reference herein without disclaimer.

BACKGROUND OF THE INVENTION

The invention relates to a method for producing an object marking, andto the object marking itself, for optical authentication of an object,wherein at least one section of a material piece of a basic material isdetermined variably and arbitrarily and/or randomly and the objectmarking is produced with the at least one section.

Product counterfeiting has become increasingly problematic. Systemsenabling the authentication of an object, especially of a product,provide remedy in this respect. These systems assign, as a rule, aunique serial number to each object and store it along with objectproperties, similar to a finger print with people. Accordingly,authentication means in this context the examination of authenticity ofa product, or more general, of any object, in particular with respect tothe question of whether the product constitutes product counterfeitingor not. In this process, particular differentiating features of theobject are generally identified and examined in that they are comparedto the, e.g. stored, features of a true object. If the objects to beauthenticated lack the appropriate differentiating features, these maybe added artificially. The main purpose of object marking as defined bythe invention is accordingly the adding of additional differentiatingfeatures to the object, which may be taken into account duringauthentication and increase reliability.

In order to protect an object property from being copied, knownsolutions make use of microscopic properties such as surface structuresor discoloration of fibers (reference). This is getting to a point whereobjects are marked with a specific DNA. A drawback of these solutions isthat these properties are only readable with specific equipment, at anyrate, however, not with commercially available cameras. The reason forthe counterfeit protection achieved by the use of such physicalproperties lies in the stochastic nature of the properties mentioned,i.e. they are practically not reproducible.

Such object marking is already known from U.S. Pat. No. 8,090,952 B2which describes a unique product marking verifiable by means of a smartphone. The product marking and/or a segment of the product marking isformed by an arbitrarily chosen section of a repeating pattern. A labelmay be arranged at an arbitrarily chosen position in the segment as anadditional security feature, wherein the label may also comprise ahologram. Since both the repeating pattern as such and the content ofthe label are defined, such product marking may be reproduced withrelatively little effort already. Since the label, apart from thearrangement, does not comprise any random elements and thus has to beanalyzed once only, a simple photocopy of the arrangement suffices to beable to duplicate the section of the pattern and the position of thelabel.

Furthermore, WO 2004/070667 A2 describes the production of a securityindicator on the basis of a random pattern which is in turn produced onthe basis of a random physical process. Although a much larger number ofrandom and hence unique differentiating features may be embedded in theproduct marking in this manner, these are also completely detectable bymeans of a simple photocopy and thus duplicatable—although withincreased effort.

US 2002/0080221 A1 describes a digital hot embossing system suitable forthe application of security features, such as holograms, in freelyselectable shapes. Although the shapes may allegedly be chosen“randomly”, there is not disclosed how this “random” is achieved, and itmust be assumed that this is a digital and hence deterministic “random”which is accordingly digitally replicable. Due to the structure of thepre-printed pattern used, it is possible to completely analyze andconsequently also reproduce the security feature already on the basis ofone single original. Moreover, the arrangement and orientation of thesecurity feature is defined by the pre-printed pattern and is hencepredictable.

EP 2 461 307 A2 illustrates a method for producing markings for theidentification and for the proof of authenticity of products. Theindividual markings are punched out of a sheet of holographicallyexposed material by means of a cutting tool.

EP 2 075 114 A2 describes a method in which labels on which, forinstance, holograms are arranged as primary identification features areproduced in individual shapes by cutting or punching from a label web.The concrete individual shape is predetermined by a computer-controlledsystem and is hence reproducible.

Finally, WO 2010/001203 A1 discloses a method for producing markings forprotection from counterfeiting which are verifiable by means of acameraphone. A web provided with a periodic pattern is cut into aplurality of identical sections, i.e. the dimensions of the sectionscorrespond exactly to the period of the pattern.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an object marking and/or amethod for producing the same, which may be examined by a commerciallyavailable programmable device with incorporated camera (e.g. a smartphone), on the one hand, and which can at the same time be replicated orcounterfeited neither by a two-dimensional color copy with sufficientlyhigh resolution nor with the aid of identical production resources.

The invention solves this object in that, in a method of the kind statedin the outset, the basic material of the material piece comprises arepeating security feature (i.e. a periodic sequence of securityfeatures) having optical properties dependent on the viewing angle, thedimensions of said security feature (which correspond to one period ofthe sequence of security features) being larger than the dimensions ofthe section, more particularly larger than the dimensions of the objectmarking, such that each section is unique and comprises only a part ofthe security feature. The section may in particular also have smallerdimensions than the material piece, such that the removal of a sectionneed not stringently result in a cut through of the material piece. Thesection may, for instance, be produced by separation, e.g. by means ofcutting or punching, or else by detachment, for instance, by means of anembossing method. Essential for the security of the invention is—alongwith the relationship of the dimensions—the arbitrary and/or randomdetermining of the section, i.e. the section is determined in the scopeof a random process. “Random” means in this context the dependence on atrue random as it occurs, for instance, in stochastic physicalprocesses. In contrast to pseudo random which is usually provided byspecific deterministic algorithms with the aid of a computer, such“true” random is not reproducible and not predictable. Security featuresmeans in this connection those features of a material and/or of thebasic material which have optical properties dependent on the viewingangle, such that it is not possible to reproduce all available opticalproperties on the basis of a two-dimensional copy. Typical securityfeatures are, for instance, water marks, a specific paper quality,specific three-dimensional printing techniques, safety threads, printingelements with tilting effect, optically variable colors, or generallyoptically variable features, e.g. in the form of kinegrams, holograms,or patterns, signs and shapes which are recognizable under a certainviewing angle only and/or change their color, as well as combinations ofthe techniques mentioned. It is to be understood that the basic materialmay also comprise a plurality of equal or similar security features aswell as any combination of equal and different security features. Suchsecurity features may, in the case of complete knowledge, be replicatedat least up to such an extent that the replicate stands up to anexamination by means of a—comparatively coarsely resolving—camera. Theobject marking in accordance with the invention, however, aggravatesreplication additionally in that the individual object marking onlydiscloses a small part of the security features of the basic material.Since this part is selected randomly, the number of object markings tobe analyzed for a replication of the basic material cannot be predicted:In some circumstances, even if all produced object markings areavailable, not all security features of the basic material aredisclosed, and an imitation of the production method is therefore notpossible. On the basis of an individual object marking it is not evenpossible to derive the periodicity of the security feature and/or thesequence of security features. On the other hand, from a joint view of aplurality of object markings it cannot be reconstructed with certaintywhether the respective sections have been taken from the same basicmaterial, i.e. there is no reliable method for reconstructing the basicmaterial. The instant invention thus achieves protection from copieswhich could otherwise be produced with the aid of identical productionresources, by the use of a random production process. Thus, even withthe knowledge and the production resources of the creator and/or theoriginal producer, a specific production of two objects with identicalproperties is not possible.

Accordingly, the above-mentioned object is solved in accordance with theinvention by an object marking of the kind stated in the outset, inwhich the basic material of the material piece has a repeating securityfeature having optical properties dependent on the viewing angle, thedimensions of said security feature being larger than the dimensions ofthe section, more particularly larger than the dimensions of the objectmarking, such that each section is unique and comprises only a part ofthe security feature. The following improvements and/or the advantagesassociated therewith apply to this effect both to the method forproducing an object marking and to the object marking itself, as well asto a set of object markings.

The advantageous properties of the object marking in accordance with theinvention are recognizable and verifiable especially by means of a setwith a plurality of object markings, wherein the section and/or thesections of every single object marking of the set differs/differ fromthe sections of all the remaining object markings of the set. This is inparticular even then true if all sections have been taken from the samebasic material. In this case the periodicity of the sequence of securityfeatures of the basic material may be recognized basically by means of asufficiently large number (dependent on the dimension of the section inrelation to the period), which does not mean, however, that the basicmaterial could be reconstructed completely by means of the same number.Moreover, it is of advantage if every section is statisticallyindependent of every other section. Contrary to this, a significantstatistic dependence and/or correlation would indicate deterministicallydefined sections which could thus be predicted and in the lastconsequence be counterfeited.

Due to the high effort of a replication as compared to the productioncosts it is particularly advantageous if the security feature of thebasic material is an optically variable feature, i.e. a material havingproperties dependent on the viewing angle, in particular a hologram.

It is further favorable if the security material and/or its opticalproperties have dimensions which correspond at least to the resolvingpower of the human eye, in particular the resolving power ofcommercially available cameras, such that the security feature isreadable and verifiable with a commercially available camera. In thecase of dimensions which correspond at least to the resolving power ofthe human eye, the security feature may also be examined by directcomparison e.g. with a plurality of simplifying images. Depending on thecamera technique used, a minimum dimension of 100 μm may, for instance,be provided. As a matter of principle, the security feature is to bereadable and verifiable with a commercially available camera withoutsubsequent enhancement and/or modification of the optics, such that thisfeature may be incorporated in an automatic examination. In particular,in this case the verifiable features and/or properties cannot only beused for verification, but also for identification of the objectmarking, i.e. the identity of the object marking may be determined onthe basis of the security features taken and/or the optical propertiesthereof (which, as stated above, illustrate a randomly determined partof the security features of the basic material). It is not necessarythat always the entire section is detectable and/or readable at once,but authentication on the basis of one or a plurality of partial regionsof the object marking, which generally does not comprise all sectionscompletely, may be allowed.

A non-deterministic and at the same time easy-to-generate contributionto the random selection of the section may be achieved in that thematerial piece is designed in the form of a band and a position of theband is selected by a random and/or non-controlled advance of the bandwhich preferably deviates from the period of the security feature of thebasic material, and the section is determined in relation to theselected position.

It is of further advantage for the selection of the security features ifthe section is determined by a variable, random selection mask, whereinthe section is determined either in correspondence with a region of thematerial piece masked by the selection mask or in correspondence with aregion of the material piece unmasked and/or spared by the selectionmask. The selection mask makes it possible to determine the portion ofthe security features of the basic material disclosed by an individualobject marking in an even more flexible manner, and to reduce the sizeof said portion.

The variable selection mask may preferably be applied on the materialpiece in the form of a partial cover, in particular in the form of alayer applied in places and/or in regions. Such a cover may selectivelycover and hence mask a part of the security features comprised in thesection. Moreover, the cover may be applied by physically random and/orchaotic processes, such that the selection mask contributes torandomness, i.e. to non-determinism, of the selection of securityfeatures used for authentication. It is irrelevant whether the coverexceeds the section or is applied within the limits of the section only.

The diversity of the variations of object markings achievable with themethod may be further increased if at least one arbitrarily and/orrandomly determined part of the material piece is removed prior to theproduction of the object marking, preferably even prior to thedetermining of the section. The part removed can accordingly no longerbe a part of the corresponding object marking.

It is furthermore particularly advantageous if at least one furthersection of the same material piece or of a further material piece of thebasic material is determined arbitrarily and/or randomly and the objectmarking is produced with the at least two sections. In this respect, itis not only the properties of the two separate sections, but also theirrelative arrangement which is preferably chosen randomly, which forms apart of the features used for the authentication of the object marking.In general, partial or complete overlappings of the sections may alsooccur, which is also absolutely desired.

In this connection a physical random of the arrangement may additionallybe introduced in that the at least two sections are mixed with an atleast temporarily liquid or paste-like carrier mass. In this process,not only the two-dimensional arrangement, but the three-dimensionalarrangement of the sections is varied and determined randomly, such thatthe sections are arranged under different viewing angles and—in the caseof optically variable features—may comprise a combination of opticalfeatures which is not even available in the basic material. Accordingly,during object marking, the section is favorably arranged along with atleast one further variable, preferably random, section of a materialpiece of the basic material in an at least temporarily liquid orpaste-like carrier mass.

If the carrier mass for producing the object marking is applied directlyon the object, the marked object becomes an inseparable part of theobject marking since it serves as a carrier for the carrier mass whichis not inherently stable, such that a detachment of the carrier massresults in the destruction of the object marking. Accordingly, in anobject with an appropriate object marking the carrier mass with thesections for forming the object marking may be applied directly on theobject or form a constituent of the object.

Alternatively, a foil may also be produced from the carrier mass.Subsequently, the object marking is produced with this foil. Theadvantage of this is that objects which do not have sufficient inherentstability (e.g. elastic substances or the like) can also be markedwithout the object marking being destroyed by the expedient use of theobject. Accordingly, the carrier mass may be processed with the sectionsas a foil for forming the object marking.

As a third possibility it has turned out to be of advantage if the atleast one section is applied on a carrier material for producing theobject marking. The carrier material may especially be a web or a sheetof a flat material, e.g. paper or a foil. Due to further stochasticprocesses in the production process, e.g. caused by minimally differentadvance speeds of the section and/or of the basic material, on the onehand, and the carrier material, on the other hand, in a seriesproduction, the position of the section may vary within the objectmarking individually and randomly, such that a positioning inaccuracy ofthe section within the object marking which is achieved in this way alsocorresponds to a “true” random and may be evaluated and thus contributesto the safety of the object marking. In particular in seriesproduction—and the associated accumulated effect e.g. of inaccuracies inadvance speed synchronization—no series with identical object markingscan thus be produced even with existing basic material and selectionprovision.

The described production variants, i.e. where the object markingcomprises a carrier mass or a carrier material, have the advantage that,due to the additional stochastic physical processes in the course of theconnection of the section with the carrier mass and/or the carriermaterial, individually deviating object markings are even achieved inthe unlikely case that a section is twice taken with a particularselection mask at the same position of the security feature and isapplied on the carrier material and/or incorporated in the carrier mass.

Furthermore, it is favorable if the same material piece and/or at leasta further section of the material piece is used for the production of atleast one further object marking. This means that only a selected partof the basic material is taken from the material piece for producing afirst section, and the remaining material which does not belong to thesection remains part of the material piece and may thus be further used.This multiple and/or repeated use of a material piece, i.e. one and thesame material piece, for producing a plurality of separate objectmarkings, in particular for different objects, makes it possible toefficiently use the quantity of required basic material, on the onehand, and, on the other hand, all sections which have already been takeninfluence the section assigned to the corresponding object marking, suchthat the reproducibility is further reduced. Moreover, in this case,sections which have been taken successively cannot or can hardly bereferred to for reconstruction of the basic material since in this casenaturally no overlappings of the sections are disclosed.

Moreover, further authentication features may be added to the objectmarking when the object marking is connected with the object, whereinthe object marking is arranged variably and randomly with respect to theobject and/or an orientation mark applied on the object. In particular,the section and/or the sections may be connected with an object in avariably determined arrangement or a random arrangement caused byproduction tolerances, such that the arrangement relative to the objectand/or to an orientation mark provided on the object forms a part of theobject marking. In this connection, an appropriate object marking may beconnected with an object, wherein the object marking is arranged withrespect to the object and/or an orientation mark applied on the objectvariably, in particular caused by production tolerances, randomly.

Moreover, it is particularly favorable in this connection if theproperties generated by the random arrangement of the object marking aredeterminable and readable with a commercially available camera. In thiscase the respective properties may be taken into account with anelectronic examination of the object marking.

The invention also relates in particular to the use of the describedobject marking in connection with a method and/or system for thedistinct marking of an object, as described in the preceding PCTapplication with file number PCT/AT2013/050121, wherein unique featuresare digitized and signed with a private key, and the unique featuresthemselves are arranged on the object or a package of the object inaddition to the signature of the digitized features, or are formed by atleast a part of the object or the package thereof, and the authenticityof the object is determined by a comparison of the unique features withthe signature of the digitized features arranged on the object or thepackage thereof and decrypted with a public key. For providing a safemethod which can be implemented easily and in a cost efficient manner,the unique features are formed by optically detectable three-dimensionalstructures or materials having optical properties differing as afunction of the viewing angle, and the digitized features are generatedwith the aid of an algorithm which is applied to at least two digitalpictures of the unique features which are taken with at least onedigital camera.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be explained further by means ofparticularly preferred embodiments to which it is not to be restricted,though, and with reference to the drawing. The drawing illustrates indetail in:

FIG. 1 schematically a material piece of a basic material having opticalproperties dependent on the viewing angle;

FIG. 2 schematically a number of examples of material pieces ofdifferent basic materials under different viewing angles;

FIG. 3 schematically the selection of a section of a material piecepursuant to FIG. 2 for producing an object marking;

FIG. 4 schematically three sequentially selected sections of a materialpiece in accordance with a random advance;

FIG. 5 for comparison schematically three sequentially selected sectionsof a material piece in accordance with a constant advance;

FIG. 6 schematically a period of a security feature of a material piece;

FIG. 7 schematically the application of different selection masks to oneand the same selection of the material piece for producing differentobject markings;

FIG. 8 schematically the combination of the sections of three materialpieces defined in accordance with different selection masks to form anobject marking; and

FIG. 9 schematically a fragmentation of a plurality of material piecesand the combination of sections in the form of pieces of each materialpiece to form an object marking.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a material piece 1 of a basic material, wherein aregion 2 of the material piece is illustrated in accordance with itsappearance under a first viewing angle α (indicated schematically by theeye 3 of the observer) and in accordance with its appearance under asecond viewing angle β. The arrow 4 indicates schematically a change ofthe viewing angle between the illustrations α, β (cf. FIG. 2). Forprotection from two-dimensional copies, a plurality of security features5 are arranged on the material piece 1, which each have differentappearances and/or more generally different optical properties underdifferent viewing angles α, β The security features 5 may, for instance,correspond to machine-readable patterns or signals. A change 4 of theviewing angle on the material piece 1 thus causes, for instance, achange of the illustrated pattern and/or sign, its coloring and/or itsvisibility.

In order to enable the evaluation with the aid of a commerciallyavailable programmable device, such as a smart phone, the opticalproperties, such as patterns and/or signs, must have certain properties.They must, for instance, have a minimum size of 100 μm×100 μm. Moreover,a sufficiently high contrast between the properties and their backgroundis required for the computer-aided image processing. This may beexpressed by differences in brightness, advantageously, however, intheir coloring or other optical properties. The patterns used maycomprise the most different characteristics, as is illustrated in FIG.2. Thus, geometric figures are as suited as the illustration ofdifferent signs. Examples of such basic materials are materials withholograms, lenticular materials, saw tooth foils, or foils forrestricting the viewing angle.

FIG. 3 illustrates the production of an object marking 6 by theapplication 7 of a section 8 in accordance with a selected region 9 ofthe material piece 1. The section 8 may be applied on an object 10 bydifferent methods, such as cold or hot embossing technologies, whereinthe object 10 may also be a carrier material belonging to the objectmarking 6. The method used for application 7 is predominantly dependenton the nature of the object 10 and/or the material piece 1, such as heatsensitivity or surface structure.

Increased protection from copying with the aid of identical productionresources is achieved by the use of a random application 7. In thisprocess, a region 9 of the material piece 1 is selected arbitrarily andthe section 8 of the material piece 1 which corresponds to the region 9is applied on the object 10. In the case of a cold or hot embossingmethod the selection of the region 9 and the application 7 are oneprocess step. The material piece 1 is available in the form of acontinuous foil of the basic material, wherein the embossing method doesnot register the positioning of the material piece 1, such that theregion 9 is selected by an arbitrary material advance and thecorresponding section 8 is applied on the object 10.

In order that the security features 5′ applied on the object 10 can bereferred to for authentication in combination with a unique seriesnumber 11, care is taken when selecting the basic material that thesecurity features 5 contained thereon have sufficiently high variationand a period exceeding the dimensions of the region 9. Since suchmaterials, for instance, holograms, regularly have periodicallyrepeating patterns, a sufficiently arbitrary selection with a givenperiod may be achieved by the choice of a suitable size of the region 9and by a suitable material advance 12 (cf. FIG. 4).

The actual variation, i.e. — broadly speaking—the number of sections tobe produced until a pattern repeats, is calculated by the lowest commonmultiple of the period of the pattern of the basic material and theselected dimension of the material advance 12, 12′, unless furthermeasures are applied for varying the sections and/or the objectmarkings. FIGS. 4 and 5 illustrate the possible effects of a favorable(FIG. 4) and/or unfavorable (FIG. 5) choice of these parameters. In FIG.4 some advantageous regions 9 of the material piece 1 are indicatedwhich are selected by a variable random material advance 12 and resultin a variation of the resulting sections 8 and hence the object markings6. In FIG. 5 the most unfavorable possible selection of regions 9 of thematerial piece 1 is illustrated, wherein the material advance 12′corresponds exactly to the period of the security features, such thatalways the same region is selected and thus always the same section 8 isused for the production of the object markings 6.

The security features 5 dependent on the viewing angle and the opticalproperties of the basic material may be completely different patterns orvariations of a pattern and/or sign, for instance, by rotation orperspective projection of the same pattern. The use of rotation andprojection yields advantages with the storing of the digital objectproperties since a smaller quantity of data is required due to bettercompressibility.

If the period of the (unchanged) security feature is relatively smalland/or only slightly larger than the dimensions of the object marking tobe produced, i.e. if the security feature (e.g. the pattern) on thematerial piece 1 repeats in short periodic intervals 13, as illustratedin FIG. 6, only little variation is achieved with the hitherto describedmethods. An increase in variation is achieved by the method forproducing an object marking by a plurality of sections 14 of a materialpiece 1, illustrated schematically in FIG. 7. Here, from a region 9selected in a first step 15, only the sections 14 corresponding to aselection mask 16 are applied on the object 10 in a second step 17.Since a static selection mask 16 does not result in an improvement ofthe variation, but merely in a smaller area of the same selection, thepattern of taking 18 of the selection mask 16 is always changed. Due tothe variable selection masks 16, 16′ a new combination of securityfeatures and hence different object markings 6 are applied on theobjects 10 even with identical selection of the region 9. By thedifferent selection masks 16 and 16′ such a change is illustratedschematically and may be achieved with an embossing method, forinstance, by the rotation of a stamp. The use of digital embossingmethods is more advantageous, wherein, for instance, the embossing punchis changed dynamically or the adhesive is applied dynamically.

An alternative or additional approach for the dynamic selection of aplurality of sections 8 of a material piece 1 without separating it is apartial covering by a further material. Here, a material sectioncorresponding to the entire selected region 9 is applied on the object10 and overlapped by a covering material having the form of a selectionmask 16. The covering material may, for instance, be a color layer whichis applied by a digital printing method. Overlapping may be performedbefore or after the selection of the material section.

A further increase in variations and in the end also in security ispossible by the method for producing an object marking 6 by a pluralityof sections 8 of a plurality of independent material pieces 1, asillustrated in FIG. 8. Due to the use of different basic materialsand/or materials with different security features the achieved variationof the resulting object marking is many times higher and a copy is thusmore difficult to obtain. The security features corresponding to thesections 8 and hence the object marking 6 have an optical appearancewhich differs with a change 4 of the viewing angle α, β.

The variation of the security features may moreover be increased by arepeated use of a, i.e. one and the same, material piece 1. Thus, forinstance, a material piece 1 which has already been used comprises gapshaving an influence on the resulting sections 8 during further use.

Furthermore, an increase in the variations is moreover possible by theremoval of arbitrary sections prior to the selection of a region 9and/or the application 7, 17 of the selected section 8 of the materialpiece 1. Thus, it is, for instance, possible to punch arbitrary patternsout of a foil before it is applied.

Moreover, a further property usable for authentication may be introducedby a variation of the position of the object marking 6 relative to theobject 10 itself or an orientation mark 19 applied on the object 10 (cf.FIG. 3).

The indirect application illustrated schematically in FIG. 9 is analternative method for producing an object marking in the scope of theinvention. Here, in a first step 20 at least one material piece 1 havingoptical properties dependent on the viewing angle and/or securityfeatures is divided into small parts and/or sections 21 which areapplied arbitrarily on the object 10 in a second step. This may, forinstance, be implemented by the chaffing of a hologram foil, the mixingof the resulting small parts 21 with a fluid or paste-like carrier mass,such as a varnish, and the application of the carrier mass along withthe small parts 21 with the aid of a printing method. In order to enablethe readability of the object marking produced this way with the aid ofa commercially available programmable device with a camera, it hasturned out favorable if the resulting small parts 21 have a minimumdiameter of 100 μm. Examples of suitable basic materials havingproperties dependent on the viewing angle are: holograms, lenticularmaterials, saw tooth foils, or foils for restricting the viewing angle.

A variant of the method for producing an object marking by means ofindirect application in accordance with the invention is theincorporation of the material parts and/or sections 21 of at least onematerial piece 1 in a foil (not illustrated), from which foilsubsequently at least one arbitrary region is selected and acorresponding section of the foil is applied on the object 10.

If an application of the parts and/or sections 21 by embedding in afurther material, i.e. a carrier material, with sufficient materialstrength is chosen, it is in particular possible to also use materialswhich themselves do not have any properties dependent on the viewingangle. This is based on the fact that the parts 21, with sufficientmaterial strength of the embedding and/or surrounding material, may havedifferent orientations, i.e. orientations which are generally notparallel to the object surface, so that properties dependent on theviewing angle result for the entirety of the arrangement. An examplethereof are parts 21 of a reflecting material which are fragmented, e.g.chaffed, and incorporated in a foil. Depending on the viewing angle thefoil such produced thus has different reflecting properties.

What is claimed is:
 1. A method for producing an object marking foroptical authentication of an object comprising: randomly determining atleast one section of a material piece of a basic material, the sectionhaving dimensions; producing an object marking comprising the at leastone section; wherein the basic material of the material piece has aperiodically repeating pattern of security features having opticalproperties dependent on the viewing angle; and wherein a period of theperiodically repeating patter is larger than the section dimensions suchthat each section is unique and comprises only a part of the pattern ofthe security features.
 2. The method of claim 1, wherein the period islarger than the object marking.
 3. The method of claim 1, wherein thesecurity features of the basic material are optically variable features.4. The method of claim 3, wherein the security features of the basicmaterial are holograms.
 5. The method of claim 1, wherein the securityfeatures and/or their optical properties have dimensions whichcorrespond at least to a resolving power of a human eye.
 6. The methodof claim 5, wherein the security features and/or their opticalproperties have dimensions that correspond to a resolving power of acommercially available camera, such that the security features arereadable and verifiable with a commercially available camera.
 7. Themethod of claim 1, wherein the material piece is designed in the form ofa band, and a position of the band is selected by a random ornon-controlled advance of the band and the section is determined inrelation to the selected position.
 8. The method of claim 7, wherein theadvance of the band deviates from the period of the periodicallyrepeating pattern of the security features of the basic material.
 9. Themethod of claim 1, wherein the section is determined by a variable,random selection mask, wherein the section is determined incorrespondence with a region of the material piece unmasked or spared bythe selection mask.
 10. The method of claim 9, wherein the variableselection mask is applied on the material piece in the form of a partialcover.
 11. The method of claim 10, wherein the variable selection maskis applied on the material piece in the form of a layer applied inplaces or in regions.
 12. The method of claim 1, wherein the at leastone section is applied on a carrier material for producing the objectmarking.
 13. The method of claim 1, wherein the object marking isconnected with the object, wherein the object marking is arrangedvariably and randomly with respect to the object or an orientation markapplied on the object.
 14. The method of claim 17, wherein theproperties generated by the random arrangement of the object marking aredeterminable and readable with a commercially available camera.
 15. Themethod of claim 1, wherein randomly determining the at least one sectionof the basis material is based on a stochastic physical process.
 16. Themethod of claim 1, wherein the determined section is removed from thematerial piece and the same material piece is used to produce at leastone further object marking.
 17. The method of claim 1, wherein theperiodically repeating pattern of the security features comprises atwo-dimensional code.
 18. The method of claim 1, wherein the section isdetermined by a variable, random selection mask, wherein the section isdetermined in correspondence with a region of the material piece maskedby the selection mask.